JPS62140605A - Selective separation membrane for liquid - Google Patents

Abstract

PURPOSE:To obtain the titled liq. separation membrane having a high separation factor, a high permeation flow rate, and an excellent membrane-forming property in a permeation vaporizing method by using a composition of a specified substituted acetylene polymer and a polymer shown by the specified formula. CONSTITUTION:The homopolymer shown by formula I (R1 is H, halogen, alkyl, etc., and R2 is aryl, groups shown by formulas IV and V, etc.) and/or the homopolymer shown by formula II (R3 is H, halogen, alkyl, etc., and R4-7 are aryl, groups shown by formula VI, etc.) or their copolymer shown by formula III or the blend with the copolymer such as the mixture of poly[1-(trimethylsilyl)-1-propyne] and poly(vinyltrimethylsilane) are dissolved in toluene. The soln. is cast over a glass sheet to obtain a filmy membrane. The membrane thus obtained has an excellent performance in separating a liq. mixture of water-ethanol, etc., by a permeation vaporizing method.

Description

[Detailed description of the invention] [Technical field] The present invention relates to a novel liquid separation membrane.

[Prior Art and its Problems] Conventionally, distillation has been commonly used to separate mixed liquids. However, distillation requires a large amount of energy and has problems in that it is difficult to separate azeotropic mixtures, substances with similar boiling points, and substances that are unstable to heat. In contrast, in recent years, separation using membranes has been researched and developed, and is expected to develop in the future as an energy-saving separation method.

Separation methods using membranes include permeation vaporization, reverse osmosis, and dialysis, depending on the separation factor and separation operation.Reverse osmosis and dialysis are used for desalination of seawater and brine, production of ultrapure water, treatment of waste liquid, etc. Some of them have already been put into practical use in the water treatment, food industry, and medical fields. Among the separation methods using membranes, the pervaporation method places the mixed liquid to be separated on one side of the membrane and separates the mixed liquid by applying reduced pressure to the other side or flowing a gas that is inert to the mixed liquid components. , - in a manner that selectively passes through the components. This separation method is not affected by osmotic pressure and has a wide range of applications as a method that allows separation of mixed solutions with a wide concentration range.

Liquid separation by pervaporation method is disclosed in Japanese Patent Application Laid-Open No. 59-203610.
, 59-203607, 59-203602, 5
A sulfonated ethylene copolymer is used for 9-4402, and a fluorine-containing polymer having an acid type functional group is used for 58-84005 and 58-89901.

However, the reason why the pervaporation method has not yet been put into practical use is because there were problems with the membrane's separation coefficient, permeation flow rate, and membrane formability.

On the other hand, the separation of liquid mixtures is of great industrial significance, and the separation of water and ethanol is particularly attracting attention from the point of view of concentrating ethanol obtained from biomass as an alternative energy source to petroleum.

As a result of extensive research using various materials, the present inventors found that the general formula [where R1 is a hydrogen atom, a halogen atom, or an alkyl group or an unsaturated alkyl group, and R2 is an aromatic, substituted aromatic, Alkyl group, aromatic substituted alkyl group, unsaturated alkyl group, or υ3-[Si-(CH2)mln-H, where m and n are 1 to 6
Integer "CH3 CH3 or -5i-X (X is the same as R2 above) CH3, and at least one hydrogen of at least one substituent of R2 may be substituted with a halogen atom.] R3CHR4 R5- 8i-R6 (wherein R3 is a hydrogen atom, a halogen atom, or an alkyl group, R4, R5, R6, and R7 are aromatic, substituted aromatic,
Alkyl group, aromatic substituted alkyl group, unsaturated alkyl group or -[(CHp)m-3i]n -CH3
m and nCH3 are integers of 1 to 6, and at least one hydrogen of at least one substituent of these R3 to R7 may be substituted with a halogen atom. ) as the main repeating unit, the general formula % formula %) (in the formula, X is O or an integer of 1 to 10, R8, R9, RI
O is aromatic, substituted aromatic, alkyl group, aromatic substituted alkyl group, unsaturated alkyl group, or CH3 [(CH2)pSilQ CH3 CH3 p, q are integers from 1 to 6, and these R8-R9 At least one hydrogen of at least one substituent may be substituted with a halogen atom. ) The present invention was developed based on the discovery that a liquid selective separation membrane mainly composed of a composition containing a polymer having as a main repeating unit has excellent performance in liquid separation.

[Means for Solving the Problems] The general formula in the present invention [wherein R1 is a hydrogen atom, a halogen atom, or an alkyl group or an unsaturated alkyl group, and R2 is an aromatic group, a substituted aromatic group, an alkyl group, an aromatic group] Group-substituted alkyl group, unsaturated alkyl group, or l-13-[5i-(CHp)mln-H, where m and n are integers of 1 to 6 CH3 CH3 or -3i-X (X is the same as R2 above) Same as CH3, and at least one hydrogen of at least one substituent of R2 may be substituted with a halogen atom. ] R3CHR4 R5-8i-R6 (wherein R3 is a hydrogen atom, a halogen atom, or an alkyl group, R4, R5, RI3. R7 is an aromatic group, a substituted aromatic group, an alkyl group, an aromatic substituted alkyl group, an unsaturated alkyl group)
s Kill group or -[(CHp)m-3iln-CH3, where m and n are integers of Hff 1 to 6, and at least one hydrogen of at least one substituent of these R3 to R7 is a halogen atom. 1 may be exchanged. ) or general formula % formula %) (wherein X is O or a positive integer, R8, R9, RIO are aromatic, substituted aromatic, alkyl group, aromatic substituted alkyl group, unsaturated alkyl group, or CH3 [(CHp)l) 5ilG-CH3CH3 pSq is an integer of 1 to 6, and at least one hydrogen of at least one substituent of these R8-R9 may be substituted with a halogen atom. > f? 1. R
As the alkyl group or unsaturated alkyl group of 3, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, allyl group, butenyl group, pentenyl group, Examples include acetylene groups.

Aromatic groups of R2, R4, R5, R6, R7, R8, R9, R10 include phenyl groups, naphthyl groups, etc., substituted aromatic groups include methylphenyl groups, dimethylphenyl groups, 1-helimethylphenyl groups, and alkyl groups, Unsaturated alkyl groups include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group,
Aromatically substituted alkyl groups such as nonyl, decyl, allyl, butenyl, and pentenyl groups include benzyl, phenylethyl, phenylpropyl, phenylbutyl, phenylpentyl, and phenylhexyl groups. The halogen atoms for R1 and R3 include fluorine, chlorine, bromine, and iodine.

-[S! (CHz) 2 (CHp)m] n-H(
m, n is an integer of 1 to 6> As a substituent, trimethylsilyl group, 1-limethylsilylmethyldimethylsilyl group, trimethylsilylethyldimethylsilyl group,
Examples include 1-helimethylsilylpropyldimethylsilyl group. Also, -3i (CHz) 2-X (X is R
The substituents represented by 2) include ethyldimethylsilyl group, propyldimethylsilyl group, butyldimethylsilyl group, pentyldimethylsilyl group, hexyldimethylsilyl group, heptyldimethylsilyl group, octyldimethylsilyl group, nonyldimethylsilyl group, Examples include decyldimethylsilyl group, phenyldimethylsilyl group, benzyldimethylsilyl group, cyclohexyldimethylsilyl group, cyclohexylmethyldimethylsilyl group, bicyclohebutynyldimethylsilyl group, and the like.

-[(CHz)m-3i(Cf-h)2]n-CH
3 (m, n is an integer from 1 to 6) or -[(CHko)p-8! (CH3) 2 IQ-C
H3(I), q is an integer of 1 to 6) as a substituent represented by 1-rimedylsilylmethyl group, 1-limethylsilylmethyldimethylsilylmethyl group, trimethylsilylethyl group, 1-limethylsilylethyldimethylsilyl An ethyl group is required. In general, examples of these substituents in which at least one hydrogen atom is replaced with a halogen atom include fluoromethyl group, difluoromethyl group, trifluoromethyl group, chloromethyl group, dichloromethyl group, 1-lichloromethyl group, and bromomethyl group. , dibromomethyl group, tribromomethyl group, fluoroethyl group, difluoroethyl group, trifluoroethyl group, perfluoroethyl group, chloroethyl group, bromoethyl group, fluoropropyl group, difluoropropyl group, trifluoropropyl group, tetrafluoropropyl group group, pentafluoropropyl group, hekyly-fluoropropyl group, perfluoropropyl group, talolopropyl group, bromopropyl group, fluorobutyl group, 1-lifluorobutyl group, perfluorobutyl group, chlorobutyl group, bromobutyl group, fluorohexyl group , 1-lifluorohexyl group, heptafluorohexyl group, perfluorohexyl group, talolohexyl group, bromohexyl group, fluorooctyl group, trifluorooctyl group, heptafluorooctyl group, tridecafluorooctyl group, perfluorooctyl group, chlorooctyl group, bromooctyl group, fluorophenyl group, difluorophenyl group, trifluorophenyl group,
Examples include perfluorophenyl group, chlorophenyl group, bromophenyl group, trifluoromethylphenyl group, chloromethylphenyl group, and bromomethylphenyl group.

Furthermore, the polymer in the present invention is a blend of a homopolymer or copolymer of general formula (1) and/or (2) having the above-mentioned substituents and a homopolymer or copolymer of general formula (3), Copolymerizing the above-mentioned repeating unit with other heptamers within a range that does not impair the present invention,
Alternatively, other polymers may be further blended.

The method for obtaining the polymer in the present invention begins with the general formula (1
) and (2), the method shown in JP-A-59-210915 and the like can be mentioned. As a general polymerization method of substituted acetylene, Japanese Patent Publication No. 51-37312, No. 52-2051L
4-43037, 55-23565, 55-307
22, JP-A No. 57-3191L No. 57-36106, No. 58-32608, No. 59-78218.17i59
-197410 and the like.

Specifically, each substituted acetylene 7mer is treated using a tungsten-based, molybdenum-based, tantalum-based, or niobium-based catalyst, and if necessary, a metal compound such as tin, silicon, bismuth, or aluminum. It is used as a cocatalyst and polymerized using a hydrocarbon or halogenated hydrocarbon as a solvent to produce 1q.

In addition, as a method for reducing 1q of the polymer of general formula (3),
JP-A-46-2093, Nametkin
), Doklad Academy Nauk
Examples include the method shown in ``Yakadem Nauk > 1, Volume 66, (5), Page 1118 (1966).

The molecular weight of these polymers used in the present invention was determined by GPC (
The number average molecular weight as calculated by polystyrene (gel permeation chromatography) is 1,000 or more, preferably 5,000 to 5,000,000, particularly 10,000 to 1,000,000. If the number average molecular weight is less than 1,000, film forming properties are poor.

The polymer used in the present invention is generally dissolved in a solvent, cast onto a suitable surface such as a glass plate or a Teflon plate, and then formed into a film by evaporating the solvent and peeled off by any means to form a film. Obtainable. Orui is
In general, it is also possible to obtain an asymmetric membrane by stopping the evaporation of the solvent midway through the method of obtaining an asymmetric membrane such as a reverse osmosis membrane and coagulating it in a suitable pseudo-solid medium. Alternatively, the film can also be obtained by hot pressing at a temperature below the decomposition point of the polymer. Alternatively, a dilute solution of these polymers can be applied directly onto a porous support, avoiding evaporation of the solvent, to form an ultra-thin film on the porous support, which can be used as a composite membrane. . In addition, a solution of these polymers is spread on a solvent (an appropriate solvent that is not visually soluble (for example, water, Song, etc.).
The ultra-thin film obtained by evaporating the solvent and laminating it on a porous support can also be used as a composite film.

The thickness of the film obtained in this way is 10 mm to 1 mm.
The value is 0.1 μm to 500 uI for a homogeneous film.
Il, as an asymmetric membrane, 0.1μlIl ~ 500μ+n
, it can be used by 10 to 1 oun as an ultra-thin composite membrane.

Further, the solvent used for preparing the solution of the polymer according to the present invention (17) may be any solvent as long as it dissolves the blend well and evaporates easily during film formation, such as benzene, Toluene, cyclohekirin,
j)/＼ Long arsenic solvents such as Kirin, oxygenated hydrocarbon solvents such as Te1-Rahydrofuran, halogenated hydrocarbon solvents such as chloroform, dichloromethane, and 4J= carbon are well used. It will be done.

The membrane thus obtained can be incorporated as a flat membrane into a liquid separation membrane device such as a spiral type, play-and-frame type, or tubular type. The membrane can also be used in the form of hollow fibers or composite hollow fibers. However, the present invention is not dependent on the shape of these membranes.

In the present invention, the liquid mixture to be separated is a mixed liquid of water-soluble row 1 substances and water, K-v is a liquid, and water-soluble organic substances are methanol, ethanol, n-propanol, Water-soluble alcohols such as i-propanol, and needles such as ethyl ether, dihydrofuran, diochirin, and water-soluble carbons such as allene, mediyl alcohol, d3 and Water-soluble carboxylic acids such as acetic acid, 1j;;
Solids are mixtures of liquids) Single bodies are methanol/methyl acetate, methanol/ethyl acetate, ethanol/G1
Examples include ethyl acid.

Among these, it is particularly effective for separating water-soluble liquids (mixtures of substances and water).

The present invention will be described in detail below with reference to Examples, in which the separation coefficient α and the permeation flow rate Q can be calculated by h1 using the following equation.

αB = (CI/C2)/(C-1/C-2>C1
: Concentration of component A in permeate (%) C2: Concentration of component B in permeate (%) C-1: Concentration of component A in feed liquid (%) C-2: Component B in feed liquid concentration (%) Q=W/A W: permeation amount per hour (k%hr) A: membrane area (T
n2〉 Example: Mix poly[1-(trimethylsilyl)-1-but[1-pin] and poly(vinyl 1-rimedylsilane) in 1:1],
A 3% 1-toluene solution was prepared in 1-1 tal.

Spread this solution onto a glass plate with a gas of 1 to 23.4 μIn and form a film with a thickness of 23.4 μIn. ′? is. Using this film, feed solution (10% ethanol aqueous solution, feed) temperature 30°C
1 supply 1 liquid side pressure 1 atm, permeate side pressure 1011111
11I! When separation was performed by pervaporation method in J, C
XEt'-d engineering Q 10.9, Q=0.20 (kq/m2・h).

[Effect of the invention] (1) High separation coefficient.

(2) High permeation flow rate.

(3) Good film formability.

4) Easy to solvent crest.

(5) The form of the membrane can be varied.

Claims (1)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (1) [In the formula, R1 is a hydrogen atom, a halogen atom, or an alkyl group or an unsaturated alkyl group, and R2 is an aromatic, substituted aromatic, or alkyl group. group, aromatic substituted alkyl group, unsaturated alkyl group, or ▲ a mathematical formula, chemical formula, table, etc. ▼ where m and n are integers from 1 to 6 or ▲ a mathematical formula, chemical formula, table, etc. ▼ (X is the above R2 ) and at least one hydrogen of at least one substituent of R1 and R2 may be substituted with a halogen atom. ] Or, there are general formulas▲mathematical formulas, chemical formulas, tables, etc.▼(2
) (In the formula, R3 is a hydrogen atom, a halogen atom, or an alkyl group, R4, R5, R6, and R7 are aromatic, substituted aromatic,
There are alkyl groups, aromatic substituted alkyl groups, unsaturated alkyl groups, or ▲mathematical formulas, chemical formulas, tables, etc.▼, where m and n are integers of 1 to 6, and at least one of these R3 to R7 substituents is One hydrogen atom may be substituted with a halogen atom. ) as the main repeating unit, there are general formulas ▲mathematical formulas, chemical formulas, tables, etc. with a weight fraction of 100% or less▼ (in the formula, X is 0 or an integer from 1 to 10, R8, R9, R1
0 is aromatic, substituted aromatic, alkyl group, aromatic substituted alkyl group, unsaturated alkyl group, or ▲ Numerical formula, chemical formula, table, etc. ▼ p and q are integers from 1 to 6, and these R8~ At least one hydrogen in at least one substituent of R10 may be substituted with a halogen atom. ) is a main repeating unit of a liquid selective separation membrane.